**multiple platform you check and run your code according specific platform **

bool isIOS = Theme.of(context).platform == TargetPlatform.iOS;
bool isAndroid = Theme.of(context).platform == TargetPlatform.android;
bool islinux = Theme.of(context).platform == TargetPlatform.linux;
bool isfuchsia = Theme.of(context).platform == TargetPlatform.fuchsia;
bool isMacOS = Theme.of(context).platform == TargetPlatform.macOS;
bool iswindows = Theme.of(context).platform == TargetPlatform.windows;

import 'dart:io' show Platform;  //at the top

String os = Platform.operatingSystem; //in your code
print(os);

所以这里有一个小工具，我用来检测平台和操作系统的反应适当。

import'dart:io' show Platform;
import 'package:flutter/foundation.dart' show kIsWeb;

class Util {

  os getPlatform() {
    if (kIsWeb) {
      return os.Web;
    } else if (Platform.isIOS) {
      return os.IOS;
    } else if (Platform.isAndroid) {
      return os.Android;
    } else if (Platform.isFuchsia) {
      return os.Fuchsia;
    } else if (Platform.isLinux) {
      return os.Linux;
    } else if (Platform.isMacOS) {
      return os.MacOS;
    } else if (Platform.isWindows) {
      return os.Windows;
    }
    return os.Unknown;
  }

  bool isWeb() {
    return (getPlatform()==os.Web);
  }

  bool isMobile() {
    os platform = getPlatform();
    return (platform == os.Android || platform == os.IOS || platform== os.Fuchsia);
  }

  bool isComputer() {
    os platform = getPlatform();
    return (platform == os.Linux || platform == os.MacOS || platform== os.Windows);
  }

}

enum os { Unknown, Web, Android, Fuchsia, IOS, Linux, MacOS, Windows }

感谢科林，最终答案是:

bool isIOS = Theme.of(context).platform == TargetPlatform.iOS;

您可以将这个扩展文件(platform_ext.dart)添加到项目中并调用任何对象

import 'dart:io';
import 'package:flutter/foundation.dart' show kIsWeb;

extension Target on Object {
  bool isAndroid() {
    return Platform.isAndroid;
  } 
  bool isIOS() {
    return Platform.isIOS;
  } 
  bool isLinux() {
  return Platform.isLinux;
  } 
  bool isWindows() {
  return Platform.isWindows; 
  }
  bool isMacOS() {
  return Platform.isMacOS; 
  }
  bool isWeb() {
  return kIsWeb; 
  }
  // ···
}

只需导入文件并调用它

   import 'platform_ext.dart';
        ....
        @override
          Widget build(BuildContext context) {
            return isAndroid()? Text("Android"):Text("Not Android");
          }

虽然defaultTargetPlatform可以工作，但我建议使用Theme.of(context). targetplatform。这样可以测试iOS行为(因为defaultTargetPlatform总是TargetPlatform)。Android正在测试中)。它还允许小部件的祖先通过将其包装在Theme小部件中来覆盖其目标平台。